Prazosin Tablets
Action and use
Alpha1-adrenoceptor antagonist.
Definition
Prazosin Tablets contain Prazosin Hydrochloride.
Content of prazosin, C19H21N5O4
90.0 to 110% of the stated amount.
Identification
Shake a quantity of the powdered tablets containing the equivalent of 10 mg of prazosin with a mixture of 10 mL of dichloromethane and 10 mL of 0.05m potassium hydroxide, filter the organic layer through absorbent cotton, evaporate to dryness and dry the residue at 60° at a pressure not exceeding 2 kPa for 2 hours. The infrared absorption spectrum of the residue, Appendix II A, is concordant with the reference spectrum of prazosin (RS 281).
Tests
Uniformity of content
Tablets containing less than 2 mg and/or less than 2% w/w of prazosin comply with the requirements stated under Tablets using the following method of analysis. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in a mixture of 2 volumes of glacial acetic acid, 2 volumes of water and 96 volumes of methanol.
0.01% w/v of diethylamine in a mixture of 2 volumes of glacial acetic acid, 2 volumes of water and 96 volumes of methanol.
Calculate the content of C19H21N5O4 in each tablet using the declared content of C19H21N5O4 in prazosin hydrochloride BPCRS.
Related substances
Carry out the method for thin-layer chromatography, Appendix III A, using the following solutions.
5 volumes of diethylamine and 95 volumes of ethyl acetate.
Any secondary spot in the chromatogram obtained with solution (1) is not more intense than the spot in the chromatogram obtained with solution (2) and not more than two such spots are more intense than the spot in the chromatogram obtained with solution (3).
Assay
Weigh and powder 20 tablets. Carry out the method for liquid chromatography, Appendix III D, using the following solutions in a mixture of 2 volumes of glacial acetic acid, 2 volumes of water and 96 volumes of methanol.
The chromatographic conditions described under Uniformity of content may be used.
0.01% w/v of diethylamine in a mixture of 2 volumes of glacial acetic acid, 2 volumes of water and 96 volumes of methanol.
Calculate the content of C19H21N5O4 in the tablets using the declared content of C19H21N5O4 in prazosin hydrochloride BPCRS.
Labelling
The quantity of active ingredient is stated in terms of the equivalent amount of prazosin.